"Production is going to move off farm and into the cities," Mr Cribb said.

"Half the world's food is going to be grown in cities using waste water from those cities.

"We humans only eat about 200 different plants. We haven't even begun to explore the earth as to what is good to eat.

"Horticulture is going to be the mainstay in these diets."

But his fellow panellists took a more here and now approach to the issues facing horticulture.

The panel consisted of Produce Marketing Association Australia and New Zealand chief executive officer, Darren Keating, Ausveg CEO James Whiteside and the University of Queensland's Professor Jimmy Botella.

Mr Whiteside posed the question of who will be the farmers of tomorrow?

"That's a much greater challenge than the industry has given thought to," he said.

"I think there is a whole long list of innovation of how we are going to grow food. That will happen in course.

"The broader question is, how do we go from a relatively agrarian horticulture to those growing in cities?"

FOCUS: PMA A-NZ CEO Darren Keating taking part in the State of the Nation panel session.

Mr Cribb's view of the future was based on green cities.

"Cities are such ugly places compared to what it's going to be when they are covered with plants and trees," Mr Cribb said.

Futuristic hydroponic cities cost money though, a point not dismissed by Mr Whiteside.

"The issue is we have enormous potential to grow more food but it takes capital and it takes people taking risks," he said.